“My furnace isn’t working” is the customer’s comment to our dispatcher Deb. “OK” replies Deb, “we can send a technician out today to take a look and get that fixed for you.”
Here’s the problem…when our technician shows up at the home, it’s not a furnace after all, it’s a boiler. Luckily, our tech has been trained to work on both but that’s not always the case. I don’t blame the homeowner, heck I don’t know the difference between an LED and a LCD television or half the stuff I buy, for that matter. It’s not the homeowner’s business to know everything in their house but it helps to “know just enough to be dangerous” as I like to say about my own knowledge of mechanical things.
So what is the difference between a furnace and a boiler because most people have used those terms interchangeably for as long as I can remember. Here’s the simplest way to remember; a funace makes hot air and a boiler makes hot water. That’s about as simple as I can make it. If there is ductwork attached to the unit, it’s probably a furnace. If there’s a bunch of water piping connected to it, it’s probably a boiler.
“What about those pieces of ductwork or PVC pipe that go outside?” Aha, good pickup. Those are the flues that bring in combustion air and discharge exhaust to and from the outside. That’s not the same as the ductwork that distributes the hot air to your living space.
“How about that piping going to the furnace? Is that hot water piping?” Again, good observation but not correct. That is most likely the natural gas, propane or oil line that feeds fuel to the unit.
There are dozens of different types of furnaces and boilers installed in homes and businesses. Their look has changed over the years as well as their efficiency and serviceability. If you ever have a question, take a picture of what you have and email or text it to your HVAC service provider and they should be able to help you.
So repeat after me…a funace makes hot air and a boiler makes hot water. Have a great day!